大规格凡纳滨对虾饲料中适宜钙磷添加水平

【目的】研究饲料不同钙、磷添加水平对大规格凡纳滨对虾的生长性能、体成分、部分血清生化指标和组织钙磷含量的影响,以确定凡纳滨对虾(Litopenaeus vannamei)饲料中钙、磷的适宜添加量。【方法】采用双因素设计,在钙添加水平为0%、0.5%、1%的条件下,分别添加质量分数0%、0.4%、0.8%、1.2%、1.6%的磷,配制15种不同钙磷水平的实验饲料,投喂初始体质量为(11.5±0.32)g的对虾8周。【结果】1)饲料钙水平极显著影响对虾的增重率(WGR)、特定生长率(SGR)、蛋白质效率(PER)和饲料系数(FCR)(P0.01),显著影响对虾的存活率(SR)(P0.05)。饲料磷水平及钙水平与磷水平的交互作用极显著影响对虾的WGR、SGR、PER、FCR和SR(P0.01)。2)饲料钙水平极显著影响对虾的全虾粗蛋白(CP)、粗脂肪(CL),肌肉CL和粗灰分(CA)的含量(P0.01);显著影响全虾CL的含量(P0.05)。饲料磷水平极显著影响全虾CP,肌肉CP、CL、CA的含量(P0.01);显著影响全虾CL、CA的含量(P0.05)。饲料钙水平与磷水平的交互作用极显著影响全虾及肌肉CP、CL、CA的含量(P0.01)。3)饲料钙水平极显著影响对虾血清碱性磷酸酶(AKP)、酚氧化酶(PO)的活性及无机磷(IP)的含量(P0.01)。饲料磷水平极显著影响对虾的血清AKP、PO的活性(P0.01);显著影响对虾的血清总胆固醇(CHOL)、甘油三酯(TG)、IP的含量(P0.05)。饲料钙水平与磷水平的交互作用极显著地影响对虾血清AKP、PO的活性(P0.01);显著地影响对虾血清TG、Ca~(2+)的含量(P0.05)。4)饲料钙水平极显著影响全虾钙磷含量、肌肉钙含量、虾壳磷含量(P0.01);显著影响对虾肌肉磷含量、虾壳钙含量(P0.05)。饲料磷水平极显著影响对虾的全虾、肌肉、虾壳的钙磷含量(P0.01)。饲料钙水平与磷水平的交互作用极显著影响全虾钙磷含量,肌肉和虾壳的磷含量(P0.01);显著影响对虾的肌肉和虾壳的钙含量(P0.05)。【结论】以SGR为判断依据,大规格凡纳滨对虾饲料中添加质量分数0.5%的钙(总钙质量分数2.15%)和1.08%的磷(总磷质量分数2.56%)时,SGR最大。     

利用小杂鱼、低值鱼提取浓缩鱼蛋白

以小杂鱼、低值鱼为原料，采用溶剂萃取法研究了溶剂种类、温度、时间和溶剂量对鱼蛋白提取过程中脱水、脱脂、脱色和脱腥的影响，筛选出提取浓缩鱼蛋白的最佳工艺条件。结果表明，在该工艺条件下制得的浓缩鱼蛋白，其蛋白质含量高达９２．２８％，脂肪含量仅为０．０９２％。     

利用小杂鱼,低值鱼提取浓缩鱼蛋白

以小杂鱼、低值鱼为原料，采用溶剂萃取法研究了溶剂种类温度、时间和溶剂量对鱼蛋白提取过程中脱水、脱脂、脱色和脱腥的影响，筛选出提取浓缩鱼蛋白最佳工艺条件。结果表明：在该工艺条件下制得的浓缩鱼蛋白提取其蛋白质含量达９２．２８％，脂肪含量仅为０．０９２％。     

水稻青优湛2植株营养规律及其与产量的构成关系

为探讨青优湛2植株营养规律及其与产量的构成关系,对不同氮肥施用量（配合施磷钾肥）的植株营养进行了研究。结果表明：施用氮素能使青优湛2极显著地增产;不同施氮量的植株氮、磷、钾以及不同生育期的植株氮、磷钾含量均达极显著差异;植株氮出现高峰值的时期随施氮数量而异;氮磷钾配合施用的植株磷含量呈向上的波浪形规律、植株钾含量呈倒“N”形规律;分化三期植株氮、始穗期的植株磷和植株钾是影响产量的最重要因子。根据研究结果,建议在“高氮、低磷、控钾”的前提下,氮、磷、钾分别采用不同的施肥原则。     

配饵中不同大豆浓缩蛋白含量对中华绒螯蟹消化酶活力的影响(英文)

研究了大豆浓缩蛋白作为饵料蛋白源对中华绒螯蟹幼蟹消化酶活力的影响,初步探讨了中华绒螯蟹对饵料蛋白源的内在适应机理。根据中华绒螯蟹的营养需求,用大豆浓缩蛋白替代鱼粉作为蛋白源配制成6种近似等蛋白等能的饵料,其中大豆浓缩蛋白在饵料中的含量分别为0、11%、22%、33%、44%和56%(分别替代鱼蛋白质量的0、18.64%、37.93%、56.90%、77.19%和100%),对照饵料全部以鱼粉作为蛋白源。用上述6种饵料喂养中华绒螯蟹50 d后,测定蟹肝胰腺各种消化酶活力。结果表明:随着饵料中大豆浓缩蛋白含量的升高,胃蛋白酶和胰蛋白酶活力均呈降低之势。当大豆浓缩蛋白含量达到44%时,与全鱼粉对照组相比,胃蛋白酶和胰蛋白酶活力显著性降低(P<0.05);同时,淀粉酶稍呈升高之势,而纤维素酶则稍呈降低的趋势;A/T比例呈显著上升的趋势,当大豆浓缩蛋白含量达44%时,与对照组有显著性差异,说明河蟹对植物蛋白有很强的适应性。     

配饵中不同大豆浓缩蛋白含量对中华绒螯蟹消化酶活力的影响

研究了大豆浓缩蛋白作为饵料蛋白源对中华绒螯蟹幼蟹消化酶活力的影响．初步探讨了中华绒螯蟹对饵料蛋白源的内在适应机理。根据中华绒螫蟹的营养需求．用大豆浓缩蛋白替代鱼粉作为蛋白源配制成6种近似等蛋白等能的饵料，其中大豆浓缩蛋白在饵料中的含量分别为0、11％、22％、33％、44％和56％（分别替代鱼蛋白质量的0、18．64％、37．93％、56．90％、77．19％和100%），对照饵料全部以鱼粉作为蛋白源。用上述6种饵料喂养中华绒螫蟹50d后．测定蟹肝胰腺各种消化酶活力。结果表明：随着饵料中大豆浓缩蛋白含量的升高，胃蛋白酶和胰蛋白酶活力均芏降低之势。当大豆浓缩蛋白含量达到44％时，与全鱼粉对照组相比．胃蛋白酶和胰蛋白酶活力显著性降低（P〈0．05）；同时，淀粉酶稍呈升高之势，而纤维素酶则稍呈降低的趋势；A／T、比例呈显著上升的趋势。半大豆浓缩蛋白含量达44％时，与对照组有显著性差异，说明河蟹对植物蛋白有很强的适应性。     

水稻青优湛2植株营养规律及其与产量的构成关系

为探讨青优湛２植株营养规律及其与产量的构成关系,对不同氮以施用量的植株营养进行了研究。结果表明;施用氮素能使青优湛２极寺增产;不同施氮量的植株氮,磷,钾以及不同生育期的植株氮,磷钾含量均达极显著差异;植株氮出现高峰值的时期随施氮数量而异;而氮磷钾配合施用的植株磷含量呈向上的波浪形规律,植株钾含量呈倒“Ｎ”形规律;分化三期植株氮,始穗期的植株磷和植株钾是影响产量的最重要因子。根据研究结果,建议在“高     

高店子幅水化学特征及水质评价

为查明高店子幅地表水和地下水的水化学特征及水环境质量现状,为区域水资源保护与开发提供理论依 据,运用数理统计分析、模糊综合评价和灌溉水水质评价方法对研究区地表水和地下水进行了分析与评价。研究 结果表明:研究区地表水水化学组分波动较大,地下水水化学组分相对较为稳定。地表水水化学类型主要为重碳 酸硫酸－钙镁型水和重碳酸－钙镁型水;地下水水化学类型主要为重碳酸－钙镁型水和重碳酸硫酸－钠 钙 镁 型 水。研究区地表水和地下水水力联系密切,水中主要离子组分来自于盐岩、石膏和碳酸盐的风化溶滤,另 外 还 存 在阳离子交换作用、蒸发浓缩作用和人类活动的共同影响。饮用水水质评价表明,５４．５％的地表水和７１．４％的地 下水适于饮用或基本适于饮用,地下水水质稍好于地表水水质;灌溉水水质评价表明,研究区地表水和地下水均 适于灌溉,合理灌溉不会造成盐害和碱害。      

热应激对肉鸡血液生化指标及内分泌机能的影响

通过检测生产性能及血液生化指标和内分泌指标，研究了热应激对肉鸡的影响，从鸡体重、平均日增重、饲料转化率及血清总蛋白、白蛋白、钙、磷、甲状腺激素（Ｔ３、Ｔ４）含量显著下降，血清钾则信参３０日龄显著下降，但血清尿素氮、氯、皮质醇含量及血清乳酸脱氢酶、肌酸磷酸激酶活性显著升高，热应激对血清钠和葡萄糖含量影响不大。     

外源酶制剂对黄颡鱼稚鱼消化酶活性、消化率及粪便氮磷含量的影响

在以鱼粉、豆粕、棉籽粕和双低菜籽粕为蛋白源的实用饲料中分别添加植酸酶1 000 IU/kg和复合酶制剂400 mg/kg,饲喂初始体质量为(1.02±0.01)g的黄颡鱼稚鱼56 d,探讨外源酶制剂对稚鱼消化酶活性、消化率及粪便氮、磷含量的影响。结果表明:与对照组比较,二实验组稚鱼胃蛋白酶活性均高于对照组(P0.05),植酸酶组稚鱼肠道蛋白酶、胃淀粉酶活性高于对照组,差异有统计学意义(P0.05)。植酸酶组稚鱼对饲料干物质、粗蛋白质、总能、灰分和磷表观消化率高于对照组,灰分和磷表观消化率也高于复合酶组,差异均有统计学意义(P0.05);复合酶组稚鱼对饲料粗脂肪、总能表观消化率高于对照组,差异有统计学意义(P0.05)。实验组稚鱼粪便氮含量与对照组均差异无统计学意义(P0.05);植酸酶组稚鱼粪便磷含量低于对照组,差异有统计学意义(P0.05)。在稚鱼实用饲料中添加植酸酶可提高消化道消化酶活性,提高其对饲料营养物质的表观消化率,减少粪便磷排放。     

山东省临沭县北部土壤养分特征及综合肥力评价

在山东省临沭县北部农耕区进行耕层土壤样品采集,并测定土壤pH、有机质、全量及速效氮磷钾等养分指标来表征土壤肥力,运用因子分析法、聚类分析法计算出所有样本土壤养分综合评价值并进行等级划分来评价土壤肥力。结果表明临沭县北部土壤酸化严重,有机质和全氮、速效钾含量较低,全钾、全磷、碱解氮、速效磷比较丰富。因子分析显示TN、OM、AK、AP、TP、pH是影响临沭县北部土壤养分综合状况的主要因素。临沭县北部土壤肥力水平偏低;土壤养分综合评价值(IFI)具体表现为：郑山街道>青云镇>玉山镇>临沭街道>蛟龙镇。     

Internal Loads and Bioavailability of Phosphorus and Nitrogen in Dianchi Lake,China

Sediments have a significant influence on the cycling of nutrient elements in lake environments. In order to assess the distribution characteristics and estimate the bioavailability of phosphorus and nitrogen in Dianchi Lake, organic and inorganic phosphorus and nitrogen forms were analysed. The 210 Pb radiometric dating method was employed to study temporal changes in the phosphorus and nitrogen pools in Dianchi Lake. The result show that the total phosphorus(TP) and total nitrogen(TN) were both at high concentrations, ranging from 697.5–3210.0 mg/kg and 1263.7–7155.2 mg/kg, respectively. Inorganic phosphorus(IP) and total organic nitrogen(TON) were the main constituents, at percentages of 59%–78% and 74%–95%, respectively, in the sediments. Spatially, there was a decreasing trend in phosphorus and nitrogen contents from the south and north to the lake centre, which is related to the distribution pattern of local economic production. The burial rates of the various phosphorus and nitrogen forms increased in same spatially and over time. Particularly in the past two decades, the burial rates doubled, with that TN reached to 1.287 mg/(cm~2·yr) in 2014. As the most reactive forms, nitrate nitrogen(NO_3-N) and ammonia nitrogen(NH_4-N) were buried more rapidly in the south region, implying that the potential for releasing sedimentary nitrogen increased from north to south. Based on their concentrations and burial rates, the internal loads of phosphorus and nitrogen were analysed for the last century. A TP pool of 71597.6 t and a TN pool of 81191.7 t were estimated for Dianchi Lake. Bioavailable phosphorus and nitrogen pools were also estimated at 44468.0 t and 5429.7 t, respectively, for the last century.     

Effect of Dietary Phosphorus on the Growth and Body Components of Juvenile Synechogobius hasta

The effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta was determined. Different percentages of dietary phosphorus (0.63, 0.77, 0.93, 1.06, 1.22 and 1.36) were tested by feeding the fish (body weight, 15.81 g ± 0.32 g; 20 individuals each group; 3 groups each percentage) at a surplus of 5%–10% above satiation for 35 d. Dietary phosphorus did not significantly affect the specific growth rate, feed intake, feed conversion ratio and protein efficiency rate. Nitrogen ...     

Effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta

The effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta was determined. Different percentages of dietary phosphorus (0.63, 0.77, 0.93, 1.06, 1.22 and 1.36) were tested by feeding the fish (body weight, 15.81 g ± 0.32 g; 20 individuals each group; 3 groups each percentage) at a surplus of 5%–10% above satiation for 35 d. Dietary phosphorus did not significantly affect the specific growth rate, feed intake, feed conversion ratio and protein efficiency rate. Nitrogen retention was found to be the highest in fish fed the diet containing 1.06% of phosphorus; however, this was not significantly different from other diets. Fish fed the diet containing 0.93% of phosphorus showed the highest phosphorus retention; similar phosphorus retention rates were found in fish fed the diets containing 0.77% and 1.06% of phosphorus. Fish fed the diet containing the highest percentage of dietary phosphorus were found to contain the least whole body lipid, lower than fish fed other diets (P<0.05). The protein content increased from 18.59% to 19.55% (although not significant) with the decrease of body lipid content (P>0.05). The contents of the whole body ash, whole body phosphorus and vertebrae phosphorus increased with dietary phosphorus percentage up to 1.06 (P<0.05), reaching a plateau after that. Dietary phosphorus did not significantly influence the muscle components (protein, lipid and moisture). Condition factor and hepatosomatic index were the highest in fish fed the diet containing 0.63% of dietary phosphorus; however, this was not significantly different from those of other diets. The second-order polynomial regression of phosphorus retention against dietary phosphorus identified a breakpoint at 0.88% of dietary phosphorus. However, the dietary requirement of phosphorus for maintaining maximum phosphorus storage determined by broken-line analysis of the contents of whole body phosphorus, and ash and vertebrae phosphorus was 1.06% of the diet.     

Landslides & debris flows formation from gravelly soil surface erosion and particle losses in Jiangjia Ravine

Gravelly soils are made up of gravel, sand, silt and clay. They are widely used in engineering applications such as rock-fill dams with clay cores, which are the main researches at present. The strength and mechanical properties of the gravelly soils are affected by the content of coarse grain, fine particles, and their adhesive states. These Properties can be verified by laboratory unconsolidated undrained triaxial tests with grain size less than 5 mm and by large scale direct-shear tests with original grain content. Fine particles of the loose gravelly slopes are released under rainfalls, alternated the structures and mechanical properties, even affected the slope stability. There are a series of large scale direct-shear tests with different coarse grain contents to study the influence of fine particles releasing and migration, results showed the strength behavior of the gravelly soils were affected by the coarse grain content （5） and the inflection coarse grain contents. In order to study the erosion features of the gravelly soil slopes on rainfall conditions and the slopes stability alteration, we had carried out one sort of artificial rainfall local and model experiments, the runoff sediment contents were monitored during the experiments. Result showed that the shapes of the slopes surface transformed periodically, runoff sediment contents were divided into five phases according to the experiment phenomena, runoff sediment contents maintained downtrend during the rain time and the downtrend was obviouslyinterpreted by one descend belt no matter the rainfall intensity and the slope angels. Particle size analysis released the deposit on the slope surface lost almost all of the clay, most of the silt and sand after the experiments, this meant the fine particles releasing, migration and accumulation process on condition of rainfall resulted in the instability factor of the slopes even induced landslide or debris flow.     

Phosphorus speciation in wetland sediments of Zhujiang (Pearl) River Estuary, China

Phosphorus fractions and adsorption-release characteristics of sediments in the Zhujiang(Pearl) River estuary wetland were investigated.Results showed that the total phosphorus(TP) content in surface sediments ranged from 648.9 mg/kg to 1064.0 mg/kg;inorganic phosphorus(IP) was the major fraction of TP and ranged from 422.5 mg/kg to 643.9 mg/kg.Among the inorganic phosphorus,the main fractions were phosphorus bound to Al and Fe(Fe/Al-P),and calcium-bound phosphorus(Ca-P),accounting for 23%–42% and 21%–67% of IP,respectively.The vertical distribution of TP contents were significantly positive correlated with organic phosphorus(Org-P) and Fe/Al-P contents.The bio-available phosphorus contents in vertical sediments varied from 128.6 mg/kg to 442.9 mg/kg,mainly existed in Fe-Al/P fraction,and increased from the bottom to top sediments.The transport of phosphorus in sediment-water interface was controlled by the soil characteristics.The active Fe and Al content was considered as the main factor that determines adsorption capacity in vegetated marsh wetland.The P buffering capacity of the sediments in vegetated marsh wetland was greater than that in mudflat wetland.The potential risk of eutrophication in the study area is high.Reducing terrestrial phosphorus discharge and preventing the sediment Fe/Al-P release to the interstitial water are the possible solutions to reduce the risk of eutrophication in estuary wetlands,and planting vegetation in estuary wetland can also reduce the release of phosphorus in surface sediment.     

Forms and Balance of Nitrogen and Phosphorus in Cage Culture Waters in Guangdong Province, China

In order to approach the characteristics of nitrogen and phosphorus pollution caused by cage culture and the balance of nitrogen and phosphorus during the process of cage culture, a monitoring was conducted in Daya Bay of Guangdong Province, China from April 2002 to Jane 2003. The results show that the concentrations of total nitrogen (TN) in the waters at the sites with five and ten years of cage culture history are 1.8 and 2.3 times of that at control site respectively. Ammonium (NH3-N) is the main form of nitrogen in spring while nitrate ( NO3 -) in winter. The concentrations of TN, total dissolved nitrogen (TDN) and dissolved organic nitrogen (DON) are highest in autumn. The concentration of phosphorus increases with the increasing of the culturing time, among which phosphate ( PO 34-) increases most obviously. The concentrations of total phosphorus (TP) and total dissolved phosphorus (TDP) are highest in autumn. The nitrogen and phosphorus are accumulated significantly in the sediment of cage culture area. The model of N balance in the cage culture area: bait (70.62%) fry (0.28%) input by tide (14.8%) release from sediment (14.3%) = harvest of adult fish (12.07%) deposition into sediment (28.75%) output by tide (56.18%) others (3.00%). The model of P balance: bait (83.11%) fry (0.17%) input by tide (12.23%) release from sediment (4.49%) = harvest of adult fish (8.43%) deposition into sediment (48.59%) output by tide (41.94%) others (1.04%). In one fish growth year, the contents of nitrogen and phosphorus in harvest of adult fish are only 17.0% and 10.1% of the contents of nitrogen and phosphorus in fish bait and fry, wherein 83% of nitrogen and more than 89% of phosphorus in fish bait became marine pollutants.     

滇池湖滨带植被时空变化及其对滇池总磷浓度的影响

滇池是中国最大的高原淡水湖泊,是长江上游生态安全格局的重要组成部分。自2008年起政府在滇池湖滨带大规模退耕还草还林,以恢复滇池及其湖滨生态。湖滨带植被对滇池总磷浓度的影响是一个长期过程,需要通过遥感长时间连续监测的数据来评价。本文以滇池和滇池湖滨带为研究区,从空间分布、季节差异2个角度,结合入湖河流总磷负荷,研究2005—2018年滇池湖滨植被时空变化对滇池总磷浓度的影响。主要结论如下：① 滇池总磷浓度由湖缘向湖心逐渐降低,并且北部和南部偏高;2005—2018年,滇池总磷浓度呈现显著下降趋势;② 2011—2018年滇池总磷浓度显著减小与湖滨带植被的拦截作用密切相关;③ 2005—2018年滇池湖滨带草本和木本植物面积都显著增加,增加最剧烈的年份是2010—2011年;④ 相比于平水期和丰水期,枯水期NDVI与强影响区总磷浓度负相关关系最强,且木本植物NDVI与强影响区总磷浓度负相关性强于草本。本文利用长时间序列数据评价滇池总磷浓度与其湖滨植被的响应关系,可为滇池湖泊生态恢复提供科学依据。     

人工堤坝影响下的黄河三角洲海岸带生态特征分析

在滨海地区,堤坝干扰对自然植被景观及土壤属性的梯度变化规律有重要的影响.本文采用统计分析和梯度分析的方法,在RS信息提取和GIS空间分析技术的支持下,从植被群落的变化入手,从样地尺度上研究堤坝对黄河三角洲海岸带土壤环境的影响并揭示堤坝干扰下,土壤属性的梯度变化规律.研究表明:(1)堤坝影响海岸带地区自然植被的盖度,并且...     

Identifying key environmental factors influencing spatial variation of water quality in upper Shitoukoumen Reservoir Basin in Jilin Province, China

Based on the observed data in monitored drainage areas and GIS spatial analysis tools, watershed basic database of Shitoukoumen Reservoir Basin was built. The multivariate analysis and redundancy analysis (RDA) were used to analyze the spatial and temporal variations of water quality, identify the key environmental factors and their patterns influencing the spatial variation of water quality, and determine the main types and forms of the non-point source (NPS) pollutant export controlled by the key environmental factors. The results show that different patterns of environmental factors lead to great changes in water quality at spatial and seasonal scales. All selected environmental factors explain 64.5% and 68.2% of the spatial variation of water quality over dry season and rainy season, respectively, which shows clear seasonal difference. Over dry season, residential land is the most important environmental factor, which possesses 35.4% of the spatial variation, and drainage area is the second key environmental factor, which possesses 17.0% of spatial variation in the total variance. Over rainy season, slope length and drainage area are the key environmental factors, which possess 29.3% of the spatial variation together. Residential land influences nitrogen export by changing NH₄ ⁺-N and particulate organic nitrogen (PON) discharge over dry season, and drainage area controls phosphorus export by regulating dissolved phosphorus (DP) drainage over dry season and phosphorus associated particulate (PAP) loss over rainy season, respectively. Although slope length is an important environmental factor, it does not influence NPS pollutant export. It is interesting that soil organic matter, as a minor environmental factor, highly determines phosphorus and nitrogen export by enhancing the DP, PAP and PON loss.